Buy a threaded one. I just got the Greddy counterweight shift knob from Cardomain ($36 shipped!!!) and it's threaded and fits perfectly. throws feel so much more solid (and fun). Yes it's metal and will get cold and hot. Has never been enough to burn me yet.

 

The GReddy one will get hot enough to burn you, it's burned me. I keep a white cloth in the glove box to cover it in the summer so the sun doesn't hit it directly while the car is sitting outside.

 

yeah i live in so cal desert and in the summer its soooo killer on the hands!!! that is why i use racing gloves when i drive, but even then you can feel it if held on long enough. and during the winter times or later in the night the knob gets pretty cold too but hey makes your shifts faster i guess... -lol- its like playing hot potato!